The present invention relates generally to a bicycle crank arm, and more particularly to an integrally-made bicycle crank arm and a method for making integrally the bicycle crank arm.
The U.S. Pat. No. 5,979,923 of the same applicant has disclosed a bicycle crank arm which is formed of a hollow crank body, a head portion fastened to one end of the hollow crank body, and a pedal hole portion fastened to other end of the hollow crank body. The head portion and the pedal hole portion are fastened with the hollow crank body by soldering and riveting.
Such a prior art bicycle crank arm as described above is neither cost-effective nor durable in view of the fact that the process of fastening the head portion and the pedal hole portion with the hollow crank body is rather time-consuming, and that the head portion and the pedal hole portion are apt to break away from the hollow crank body.
It is the primary objective of the present invention to provide a bicycle crank arm which is made integrally and is provided with an elongated cavity.
It is another objective of the present invention to provide a method for making integrally a bicycle crank arm.
The features and the advantages of the present invention will be more readily understood upon a thoughtful deliberation of the following detailed description of the present invention with reference to the accompanying drawings.